class ValueString(object):

	_value = None

	def __init__(self, value = None):

		self.set(value)

	def set(self, value = None):

		self._value = value
		return self

	def get(self):

		return self._value

	def isEmpty(self):

		return self._value is None

	def isEquals(self, value):

		if(self._value is None):
			return value is None

		return self._value == value

	def isContains(self, value):

		return self.isEquals(value)